Viewing 40 posts - 1 through 40 (of 41 total)
  • is 100mph on a flat road on a bike really doable?
  • PeaslakeDave
    Free Member
    cynic-al
    Free Member

    Hasn’t that position been tried already?

    I doubt he’ll do it.

    paulrockliffe
    Free Member

    Why has he put a set of cranks in that position?

    cynic-al
    Free Member

    I’m assuming it’s not finished yet.

    TandemJeremy
    Free Member

    Red the piece – that is an extra shaft so as to get extra igh gearing without a huge chainring. the cranks will be where his feet are when prone

    Previous attempts have been done in a feet first position I think – prone should have a slight aero advantage but will be hellish to handle.

    RealMan
    Free Member

    With a chainring that close to your groin and your chin nearly resting on the front tyre, I wouldn’t fancy it. Can’t quite see how it’s going to work either – one slip and you’re going to lose a lot of skin if you rub your leg against that rear tyre.

    mudshark
    Free Member

    He’s a crazy genius!

    cynic-al
    Free Member

    You’d think a brace would be needed for his shoulders to push against.

    Ah…I’ve seen how if will get the extra power needed…

    To reach that speed, he will be pedalling in a gear, which is around three
    times bigger than the top gear on a road racing bike. The pedals turn a
    chain which drives one set of gears, which then transfer the power to the
    rear wheel through a second chain, doubling the pedal power of a
    conventional bike.

    GreenRoom
    Free Member

    If anyone can make it happen, it’s the Flying Scotsman. Go Obree!

    float
    Free Member

    Ah…I’ve seen how if will get the extra power needed…

    lol, makes you wonder why he doesnt put another chain and cassette in there for three times the power.

    njee20
    Free Member

    Nuts. Sod that.

    Duggan
    Full Member

    100mph on that 😯

    No. F**king. Thanks.

    Good luck to him though, hope he does it.

    jambalaya
    Free Member

    I thought 29ers where the way to go fast, those look like BMX wheels ?

    Kuco
    Full Member

    Don’t know if its doable but I really hope he makes it.

    ampthill
    Full Member

    I reall hope he succeds and he had has a great track record

    But 100 mph will be a huge over the last reocord

    He is an inspiration

    There’s a less dumbed down, sensationalist article here.

    Graeme Obree is probably the greatest living character in any sport.
    I think every single British cycling related business* should be ashamed of themselves for not getting involved in supporting him.

    *Not yer average LBS of course, the ones who actually make bike stuff.

    andrewy
    Full Member

    Not according to Mike Burrows, who knows a bit about this sort of thing. Have a listen to his interview (part 2) on the bike show podcast http://www.thebikeshow.net/

    Pigface
    Free Member

    Good luck to him but having had the misfortune to have stayed in Battle Mountain Nevada he should have all the incentive he needs to get away from the place as fast as he can. 100mph no problem 😀

    andrewy, it’s over 30 minutes long. Can you summarise it ?

    kcr
    Free Member

    I had a wee shot (back in the mid 90s) on a bike built to a similar design by Venom Cycles. I think they constructed it for a customer in London. It worked, but from what I remember, the steering was a bit twitchy.
    I suspect 100mph is unlikely. In the last 20 years the record has gone from 68mph to 82mph.
    http://www.ihpva.org/hpvarec3.htm#nom01
    However, in the past 10 years they have only added about 2mph, so I guess a lot of the big gains from technical innovation have already been made, and now the teams are chipping away with marginal improvements to overcome the basic limits imposed by the physics and power requirements.
    The leading teams are pretty sophisticated these days. It is interesting to contrast Obree’s approach with the extremely high-tech project run by the students from Delft University. Some of the videos on their website are amazing:
    http://hptdelft.nl/en/
    I heard Obree speak a few months ago, and he remains an entertaining and amazingly inspirational character. Quite apart from all the technical innovation and left field thinking, he clearly has that extreme focus and self-belief that all exceptional athletes possess. Good luck to him.

    andrewy
    Full Member

    MTG, essentially Burrows thinks that person simply can’t produce enough power to overcome the drag. He mentions one HPV design where they were testing the wind drag, which was pretty good. Then they added the wheels, which poked out a couple of inches from under the cowling, and they doubled the drag! I do hope Obree does it, but it seems unlikely.

    bm0p700f
    Free Member

    I doiubt it as to go from 82 mph to 100 mph will require 80% more power assuming Obree has the same drag coefficient and frontasl area as the rider in the 82 mph record.

    His drag CdA value would have to be 0.0237 for this to succed whichout windtunnel testing it is impossible to know the cd value. A aero cowling would be needed to recuse the cd value down to about 0.14, if that where possible then the attempt might suceed. I am assuming a peak power output here of 1300W which is possible in very short sprints.

    TandemJeremy
    Free Member

    bm0p700f

    By going prone not reclined Obree I guess intends to get a lower drag coefficient and frontal area compared to recumbent – no need for a bubble on top to see out of head shoulders hips feet all in a line

    cynic-al
    Free Member

    you have to wonder if the frontal area will be much smaller…pedaling legs and feet must account for a lot of it, and his are at the back, where you want a taper.

    I guess he’s got low Q factor sorted tho.

    andyl
    Free Member

    Always admired him when I was a kid for his constant innovation and sticking a finger up to the guys spending thousands on bikes but the mention of him living in a one bedroom flat seemed quite sad so I looked up his wiki page, quite an interesting and sad read: http://en.wikipedia.org/wiki/Graeme_Obree

    I hope he makes the record.

    aracer
    Free Member

    By going prone not reclined Obree I guess intends to get a lower drag coefficient and frontal area compared to recumbent – no need for a bubble on top to see out of head shoulders hips feet all in a line

    Whilst the record is held on a bike like that, you’ll find it’s not actually necessary, and others have built bikes without a bubble to see out of (using a camera instead).
    http://www.recumbents.com/wisil/coslinger/coslinger_special.htm

    The most obvious issue with Obree’s design is that he’s quite high up – is going to be difficult to keep the frontal area down with a vehicle which is likely to be taller than the “traditional” speed record machines where they sit between the wheels (legs either side of the front wheel).

    Maybe he can break the record – you’d have to give him a chance – but 100mph seems extremely unlikely.

    bencooper
    Free Member

    I think every single British cycling related business* should be ashamed of themselves for not getting involved in supporting him.

    *Not yer average LBS of course, the ones who actually make bike stuff.

    Well he got those tyres from me 🙂

    However he’s more of a go-it-alone type, I think more happy to build stuff himself rather than work with others. He’s not talked to the BHPC about it at all, according to Mike Burrows.

    tomlevell
    Full Member

    The real motivation is to get the record I suspect. 100mph make the press take notice. His main advantage over recent attempts our the pilot. He can go to places of pain I would think few could.

    richmars
    Full Member

    Sort of related, the film about Obree is on BBC2 tonight:
    The Flying Scotsman

    speaker2animals
    Full Member

    I”n not convinced he”s high enough. To my mind both std safety bike and recumbent have the thighs forward of the body to generate power. It’s hard to see from pic but to me that design doesn’t appear to get his legs right. But then it is a photo of a part made frame.

    He might break record but doubt the ton is on.

    Good luck fella.

    unovolo
    Free Member

    As a uneducated Oaf I was always of the understanding that one of the most aerodynamic shapes was that of a rain drop ie.Largish rounded frontal area tapering down to a point at the rear.

    If you were to loosely draw a line around Obree and the bike? in the pic it resembles a raindrop (Well it does to me).

    I have no idea if he will break the record or 100mph but can say goodluck to him for trying.

    fisha
    Free Member

    unovolo,

    my understanding was the bulb at the front, taper rear was best for heavier fluids like water ( which is why large tankers have the bulb at the front )

    and that air is more like pointer front, shorter rear.

    As for Obree … he’s nuts … but a really nice guy to talk to in person. Definitely one of my more enjoyable commutes to work was cycling along beside him.

    AlexSimon
    Full Member

    I think his main problem will be getting a rideable bike built. With a fairing that doesn’t let the rest of his idea down.

    His last bike (super long top tubed track bike), proved to be unrideable on the track (which I still can’t quite understand tbh). Interestingly, even so, the UCI immediately came up with a rule to ban it!

    I’d really really like him to be right though. Or at least some of his ideas having merit. So far many HPV enthusiasts have totally dismissed his riding position as a joke (while they try and eek out an extra 0.05% from existing designs).

    scaredypants
    Full Member

    I bloody love O’Bree !

    I’d send him a few quid if he had a paypal for this (haven’t looked too hard, I admit 😳 )

    Gary_M
    Free Member

    Yeh you love him so much you don’t know how to spell his surname. 😆

    Scariest bit would be training on the A78, not a very nice road to ride on even on a ‘normal’ bike, if he survives that then I hope he gets the record.

    scaredypants
    Full Member

    ah, well, we never married so haven’t ever written it before

    (unrequited, see ? 😥 )

    brakes
    Free Member

    I was always of the understanding that one of the most aerodynamic shapes was that of a rain drop

    raindrops are spherical (most of the time)

    rockitman
    Full Member

    “Obree’s new machine is being assembled at his one-bedroom flat in Saltcoats, North Ayrshire, in the kitchen which doubles as his workshop. He has already scavenged parts for the machine’s shoulder rests from an old saucepan.”

    I think we can assume that Graeme is single.

    How many of us would have a kitchen like that though if in the same boat 🙂

    HermanShake
    Free Member

    I’ve just up on him, what an inspiring man!

    He’s certainly determined enough and a capable builder. I really hope he breaches the 82.8, not sure if he can hit the 100.

    rockitman
    Full Member

    Yep, definitely someone to be admired. One of those people who just looks at life from a different position to the masses.

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